Staging: android: lowmemorykiller: Don't count free space unless it meets the specified limit by itself

From: Arve Hjønnevåg <arve@android.com>

This allows processes to be killed when the kernel evict cache pages in
an attempt to get more contiguous free memory.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Cc: David Rientjes <rientjes@google.com>
Cc: San Mehat <san@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/android/lowmemorykiller.c

@@ -58,20 +58,25 @@ static int lowmem_shrink(int nr_to_scan, gfp_t gfp_mask)
 	int min_adj = OOM_ADJUST_MAX + 1;
 	int selected_tasksize = 0;
 	int array_size = ARRAY_SIZE(lowmem_adj);
-	int other_free = global_page_state(NR_FREE_PAGES) + global_page_state(NR_FILE_PAGES);
+	int other_free = global_page_state(NR_FREE_PAGES);
+	int other_file = global_page_state(NR_FILE_PAGES);
 	if(lowmem_adj_size < array_size)
 		array_size = lowmem_adj_size;
 	if(lowmem_minfree_size < array_size)
 		array_size = lowmem_minfree_size;
 	for(i = 0; i < array_size; i++) {
-		if(other_free < lowmem_minfree[i]) {
+		if (other_free < lowmem_minfree[i] &&
+		    other_file < lowmem_minfree[i]) {
 			min_adj = lowmem_adj[i];
 			break;
 		}
 	}
 	if(nr_to_scan > 0)
-		lowmem_print(3, "lowmem_shrink %d, %x, ofree %d, ma %d\n", nr_to_scan, gfp_mask, other_free, min_adj);
-	rem = global_page_state(NR_ACTIVE) + global_page_state(NR_INACTIVE);
+		lowmem_print(3, "lowmem_shrink %d, %x, ofree %d %d, ma %d\n", nr_to_scan, gfp_mask, other_free, other_file, min_adj);
+	rem = global_page_state(NR_ACTIVE_ANON) +
+		global_page_state(NR_ACTIVE_FILE) +
+		global_page_state(NR_INACTIVE_ANON) +
+		global_page_state(NR_INACTIVE_FILE);
 	if (nr_to_scan <= 0 || min_adj == OOM_ADJUST_MAX + 1) {
 		lowmem_print(5, "lowmem_shrink %d, %x, return %d\n", nr_to_scan, gfp_mask, rem);
 		return rem;